EXPOSURE TO BPA DISRUPTS WNT SIGNALING PATHWAY DURING POSTNATAL DIFFERENTIATION OF THE OVIDUCT IN BROAD-SNOUTED CAIMAN (Caiman latirostris).

GALOPPO GH; LUQUE EH; KASS L; CANESINI G; MUÑOZ-DE-TORO M

Buenos Aires

Jornada; XVIII Jornadas Anuales Multidisciplinarias Sociedad Argentina de Biología; 2016

Sociedad Argentina de Biología

Wnt molecules and β-catenin control postnatal female reproductive tract development through canonical (β-catenin -dependent) or non-canonical pathways. These molecules are sensitive to endocrine-disrupting compounds (EDCs) and the oviduct is a target organ of EDCs action. Our aims were to establish the ontogeny of temporal and spatial expression patterns of wnt-5a, wnt-7a and β-catenin in C. latirostris oviducts from neonatal to pre-pubertal juvenile caimans, and to evaluate the effect of BPA early postnatal exposure. C. latirostris females raised in control conditions were euthanized at neonatal, early and late postnatal or juvenile stages. Early postnatal caimans were injected (sc) twice, 7 days apart, with 17-β estradiol (E2) (0.014 or 1.4ppm) or BPA (1.4 or 140 ppm) and euthanized 7 days after last injection. Oviductal wnt5a, wnt7a and β-catenin protein expressions were assessed by immunohistochemistry. Epithelial wnt-7a and subepithelial wnt-5a levels increased as oviduct differentiation advances showing a mutual feedback in the juvenile stage. Epithelial membrane-associated β-catenin expression was not correlated to wnts levels. All the treatments, but BPA 1.4ppm reduced wnt-7a expression, whereas E2 1.4ppm and BPA 1.4ppm decreased wnt-5a levels. BPA 1.4ppm also modified CTNNB expression. Our results suggest that postnatal development of C. latirostris oviduct is controlled by wnt signaling pathway and that early postnatal exposure to xenoestrogens could disrupt this process leading to histofunctional changes that could impair reproductive health later in life.